Exact Calculation of Light Scattering from a Particle on a Mirror

Exact methods have been developed for calculating light scattering from particles on a perfectly reflecting surface. The computed solutions obey Maxwells equations and the appropriate boundary conditions. A brief discussion of the theory is followed by a presentation and discussion of selected scattering results. Comparisons are made with the predictions of Youngs forward scatter Mie theory model. Under certain conditions the exact results differ significantly from Mie theory. The exact differential cross sections exhibit large amplitude oscillations that are not predicted by Mie theory. Me bidirectional reflectance distribution function BRDF is also calculated using exact scattering theory for both spherical and hemispherical particles that are both absorptive complex index of refraction and nonabsorptive real index of refraction. These exact BRDF results are compared to the predictions of Youngs model.